Mode of cold-rolling tubes



(No Model.)

, G. H. EVERSON.

MODE OF GOLD ROLLING TUBES.

No. 430,008. Patented June 10, 1890.

E 1 m I \E m: cili v mw UNIT D STATES PATENT OFFICE.

GEORGE H. EVERSON, OF PITTSBURG, PENNSYLVANIA.

MODE OF COLD-ROLLING TUBES.

SPECIFICATION forming part of Letters Patent No. 430,008, dated June 10, 1890.

Application filed November 1E3, 1889. Serial No. 330,201. (No model.)

To all whom, it may concern.-

Be it known that I, GEoRe-E H. EVERSON, of Pittsburg, in the county of Allegheny and State of Pennsylvania,have invented certain new and useful Improvements in Process of Cold-Rolling Metallic Tubes or Pipes; and I do hereby declare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which it pertains to make and useit, reference being had to the accompanying drawings, which form part of this specification.

My invention relates to an improved process of cold-rolling metallic tubes or pipes; and it consists in placing inside of the pipe a hardened mandrel having a less diameter than the inside of the tube or pipe which is to be rolled, and filling or partially filling the space between the mandrel and the inside of the pipe with oil and graphite or other lubricating material, and then passing the tube with the mandrel inside of it through suitable grooves in hard-chilled rolls, as will be more fully described hereinafter.

The object of my invention is to cold-roll tubes or pipes for the purpose of reducing them in size and thickness and increasing their elasticity and strength and to finish and polish their outer surfaces.

Figure 1 represents a vertical section of a machine for carrying my process into operation. Fig. 2 is an end view of the same. Fig. 3 shows the finishing-rolls.

I first take a tube or pipe of the required length, size, and thickness and place insideof it a hardened mandrel of slightly less diameter than the interior of the pipe and of greater length than the length of the tube or pipe which is to be rolled. Between the inner surface of the pipe and the outer surface of the mandrel I place a suitable quantity of graphite and oiloranyothersuitable lubricant, which will prevent the pipe from adhering to the mandrel after passing through the reducin g-rolls, and which will permit the pipe as it is elongated to slide or move along the mandrel without adhering to it. The mandrel must be harder than the pipe or tube, so that the shape of the mandrel will not be changed nor the mandrel lengthened while the pipe or tube is being rolled. With the mandrel inside of the tube 'and the lubricant between the tube and the mandrel the section of the pipe or tube is passed through a pair of grooved chilled rolls, which roll, compress, and lengthen out the pipe about two-thirds of its circumference. After the pipehasbeen passed through the rolls once it is turned partially round and passed through a second time, so as to have that portion which was not acted directly upon by the rolls rolled in the same manner as the other portion. The grooves in the reducing-rolls being wider or of greater diameter at the sides Where the edges of the rolls meet than at those points Where the rolls'com-e in contact with the pipe for the purpose of reducing it, the opposite sides of the pipe are expanded or made to bulge out, as shown in Fig. 2. The pipe in passing through the rolls, besides having its thickness decreased, is lengthened, and has its elasticity and strength increased, and the rolls polish and finish the outer surface of the pipe better than if it had been passed through a polishing-machine. Another advantage gained is that the pipe or tube after being thus rolled has its thickness or diameter made uniform from one end to theother, thus adapting the tubes for use wherever an elastic tube is required, or one which has an even uniform diameter from end to end, or where a finely-polished surface is needed. After the tube and the mandrel have been passed a suitable number of times through the grooved rolls, so as to reduce the pipe to the desired thickness, the mandrel is removed from the pipe, and then the pipe is passed without the mandrel through rolls having perfectly-round grooves in them, as shown in Fig. 3.

Having thus described my invention, I claim- 1. The process herein described of coldrolling metal tubes or pipes, consisting in placing inside of the tube a man drel of slightlyless diameter than the interior of the pipe or tube, placing a suitable lubricant between the mandrel and the pipe, and then passing the pipe and the mandrel through a pair of grooved rolls, so as to reduce the diameter of the pipe or tube and elongate it at the same time that the surface of the tube is polished and finished, substantially as described.

2. The process herein described of coldrolling metallic tubes or pipes, consisting in the mandrel through a pair of rolls provided first placing inside of the tube a mandrel of witha round groove,substantially as specified. -10 greater length than the tube, placing a suit- In testimony whereof I affix my signature able lubricanthetween the tube and the manin presence of two Witnesses.

drel, then passing the tube with the mandrel GEORGE H. EVERSON. placed inside of it asuita-ble numberof times XVitnesses: through a pair of grooved reducing-rolls, and F. A. LEHMANN,

then finishing the pipe by passing it Without H. J. ENNIS. 

